The Plant-Transpiration Response to Vapor Pressure Deficit (VPD) in Durum Wheat Is Associated With Differential Yield Performance and Specific Expression of Genes Involved in Primary Metabolism and Water Transport

The effect of mycorrhizal fungi on gas exchange of micropropagated guava plantlets (Psidium guajava L.) during acclimatization and plant establishment was determined. Guava plantlets (Psidium guajava L. cv. `Media China') were asexually propagated through tissue culture and acclimatized in a glasshouse for eighteen weeks. Half of the plantlets were inoculated with ZAC-19, which is a mixed isolate containing Glomus etunicatum and an unknown Glomus spp. Plantlets were fertilized with modified Long Ashton nutrient solution containing 11 (g P/ml. Gas exchange measurements included photosynthetic rate (A), stomatal conductance (gs), internal CO2 concentration (Ci), transpiration rate (E), water use efficiency (WUE), and vapor pressure deficit (VPD). Measurements were taken at 2, 4, 8 and 18 weeks after inoculation using a LI-6200 portable photosynthesis system (LI-COR Inc. Lincoln, Neb., USA). Two weeks after inoculation, noninoculated plantlets had greater A compared to mycorrhizal plantlets. However, 4 and 8 weeks after inoculation, mycorrhizal plantlets had greater A, gs, Ci and WUE. At the end of the experiment gas exchange was comparable between noninoculated and mycorrhizal plantlets.

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Is There Daily Growth Hysteresis versus Vapor Pressure Deficit in Cherry Fruit?

Horticulturae ◽

10.3390/horticulturae7060131 ◽

2021 ◽

Vol 7 (6) ◽

pp. 131

Author(s):

Matteo Zucchini ◽

Arash Khosravi ◽

Veronica Giorgi ◽

Adriano Mancini ◽

Davide Neri

Keyword(s):

Vapor Pressure ◽

Vapor Pressure Deficit ◽

Fruit Growth ◽

Hysteresis Curve ◽

Growth Stages ◽

Fourth Stage ◽

The Third ◽

Third Stage ◽

Rainy Days ◽

Clockwise Hysteresis

The growth of cherry fruit is generally described using a double sigmoid model, divided into four growth stages. Abiotic factors are considered to be significant components in modifying fruit growth, and among these, the vapor pressure deficit (VPD) is deemed the most effective. In this study, we investigated sweet cherry fruit growth through the continuous, hourly monitoring of fruit transversal diameter over two consecutive years (2019 and 2020), from the beginning of the third stage to maturation (forth stage). Extensometers were used in the field and VPD was calculated from weather data. The fruit growth pattern up to the end of the third stage demonstrated three critical steps during non-rainy days: shrinkage, stabilization and expansion. In the third stage of fruit growth, a partial clockwise hysteresis curve of circadian growth, as a response to VPD, appeared on random days. The pattern of fruit growth during rainy days was not distinctive, but the amount and duration of rain caused a consequent decrease in the VPD and indirectly boosted fruit growth. At the beginning of the fourth stage, the circadian growth changed and the daily transversal diameter vs VPD formed fully clockwise hysteresis curves for most of this stage. Our findings indicate that hysteresis can be employed to evaluate the initial phenological phase of fruit maturation, as a fully clockwise hysteresis curve was observable only in the fourth stage of fruit growth. There are additional opportunities for its use in the management of fruit production, such as in precision fruit farming.

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Towards In Vivo Monitoring of Ions Accumulation in Trees: Response of an in Planta Organic Electrochemical Transistor Based Sensor to Water Flux Density, Light and Vapor Pressure Deficit Variation

Applied Sciences ◽

10.3390/app11114729 ◽

2021 ◽

Vol 11 (11) ◽

pp. 4729

Author(s):

Davide Amato ◽

Giuseppe Montanaro ◽

Filippo Vurro ◽

Nicola Coppedé ◽

Nunzio Briglia ◽

...

Keyword(s):

Vapor Pressure ◽

Flux Density ◽

Precision Agriculture ◽

Vapor Pressure Deficit ◽

Accumulation Rate ◽

Xylem Sap ◽

Water Flux ◽

Electrochemical Transistor ◽

Olive Trees

Research on organic electrochemical transistor (OECT) based sensors to monitor in vivo plant traits such as xylem sap concentration is attracting attention for their potential application in precision agriculture. Fabrication and electronic aspects of OECT have been the subject of extensive research while its characterization within the plant water relation context deserves further efforts. This study tested the hypothesis that the response (R) of an OECT (bioristor) implanted in the trunk of olive trees is inversely proportional to the water flux density flowing through the plant (Jw). This study also examined the influence on R of vapor pressure deficit (VPD) as coupled/uncoupled with light. R was hourly recorded in potted olive trees for a 10-day period concomitantly with Jw (weight loss method). A subgroup of trees was bagged in order to reduce VPD and in turn Jw, and other trees were located in a walk-in chamber where VPD and light were independently managed. R was tightly sensitive to diurnal oscillation of Jw and at negligible values of Jw (late afternoon and night) R increased. The bioristor was not sensitive to the VPD per se unless a light source was coupled to trigger Jw. This study preliminarily examined the suitability of bioristor to estimate the mean daily nutrients accumulation rate (Ca, K) in leaves comparing chemical and sensor-based procedures showing a good agreement between them opening new perspective towards the application of OECT sensor in precision agricultural cropping systems.

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HIGH VAPOR PRESSURE DEFICITS DECREASE LEAF AREA AND INCREASE LEAF WATER TRANSPORT IN FLOWER STEMS IN SOILLESS CULTURE

Acta Horticulturae ◽

10.17660/actahortic.2007.751.50 ◽

2007 ◽

pp. 395-400

Author(s):

F. Liu ◽

Y. Wu ◽

Y. Cohen

Keyword(s):

Vapor Pressure ◽

Leaf Area ◽

Water Transport ◽

Leaf Water ◽

Soilless Culture ◽

High Vapor Pressure ◽

High Vapor

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Grape Berry Transpiration Is Determined by Vapor Pressure Deficit, Cuticular Conductance, and Berry Size

American Journal of Enology and Viticulture ◽

10.5344/ajev.2015.15038 ◽

2015 ◽

Vol 66 (4) ◽

pp. 454-462 ◽

Cited By ~ 19

Author(s):

Y. Zhang ◽

M. Keller

Keyword(s):

Vapor Pressure ◽

Vapor Pressure Deficit ◽

Grape Berry ◽

Berry Size

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Molecular and physiological characterization of the effects of auxin-enriched rootstock on grafting

Horticulture Research ◽

10.1038/s41438-021-00509-y ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Longmei Zhai ◽

Xiaomin Wang ◽

Dan Tang ◽

Qi Qi ◽

Huseyin Yer ◽

...

Keyword(s):

Callus Formation ◽

Ethylene Biosynthesis ◽

Union Formation ◽

Biosynthetic Gene ◽

Graft Union ◽

Specific Expression ◽

Physiological Characterization ◽

Graft Healing ◽

Expression Of Genes ◽

Or Gene

AbstractsGrafting is a highly useful technique, and its success largely depends on graft union formation. In this study, we found that root-specific expression of the auxin biosynthetic gene iaaM in tobacco, when used as rootstock, resulted in more rapid callus formation and faster graft healing. However, overexpression of the auxin-inactivating iaaL gene in rootstocks delayed graft healing. We observed increased endogenous auxin levels and auxin-responsive DR5::GUS expression in scions of WT/iaaM grafts compared with those found in WT/WT grafts, which suggested that auxin is transported upward from rootstock to scion tissues. A transcriptome analysis showed that auxin enhanced graft union formation through increases in the expression of genes involved in graft healing in both rootstock and scion tissues. We also observed that the ethylene biosynthetic gene ACS1 and the ethylene-responsive gene ERF5 were upregulated in both scions and rootstocks of the WT/iaaM grafts. Furthermore, exogenous applications of the ethylene precursor ACC to the junction of WT/WT grafts promoted graft union formation, whereas application of the ethylene biosynthesis inhibitor AVG delayed graft healing in WT/WT grafts, and the observed delay was less pronounced in the WT/iaaM grafts. These results demonstrated that elevated auxin levels in the iaaM rootstock in combination with the increased auxin levels in scions caused by upward transport/diffusion enhanced graft union formation and that ethylene was partially responsible for the effects of auxin on grafting. Our findings showed that grafting success can be enhanced by increasing the auxin levels in rootstocks using transgenic or gene-editing techniques.

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